/*
 **********************************************************************
 ** md5.h -- Header file for implementation of MD5                   **
 ** RSA Data Security, Inc. MD5 Message Digest Algorithm             **
 ** Created: 2/17/90 RLR                                             **
 ** Revised: 12/27/90 SRD,AJ,BSK,JT Reference C version              **
 ** Revised (for MD5): RLR 4/27/91                                   **
 **   -- G modified to have y&~z instead of y&z                      **
 **   -- FF, GG, HHmodified to add in last register done            **
 **   -- Access pattern: round 2 works mod 5, round 3 works mod 3    **
 **   -- distinct additive constant for each step                    **
 **   -- round 4 added, working mod 7                                **
 **********************************************************************
 */

/*
 **********************************************************************
 ** Copyright (C) 1990, RSA Data Security, Inc. All rights reserved. **
 **                                                                  **
 ** License to copy and use this software is granted provided that   **
 ** it is identified as the "RSA Data Security, Inc. MD5 Message     **
 ** Digest Algorithm" in all material mentioning or referencing this **
 ** software or this function.                                       **
 **                                                                  **
 ** License is also granted to make and use derivative works         **
 ** provided that such works are identified as "derived from the RSA **
 ** Data Security, Inc. MD5 Message Digest Algorithm" in all         **
 ** material mentioning or referencing the derived work.             **
 **                                                                  **
 ** RSA Data Security, Inc. makes no representations concerning      **
 ** either the merchantability of this software or the suitability   **
 ** of this software for any particular purpose.  It is provided "as **
 ** is" without express or implied warranty of any kind.             **
 **                                                                  **
 ** These notices must be retained in any copies of any part of this **
 ** documentation and/or software.                                   **
 **********************************************************************
 */

/* typedef a 32 bit type */
typedef unsigned int UINT4;

/* Data structure for MD5 (Message Digest) computation */
typedef struct {
    UINT4 i[2];                   /* number of _bits_ handled mod 2^64 */
    UINT4 buf[4];                                    /* scratch buffer */
    unsigned char in[64];                              /* input buffer */
    unsigned char digest[16];     /* actual digest after MD5Final call */
} MD5_CTX;

/*
 **********************************************************************
 ** End of md5.h                                                     **
 ******************************* (cut) ********************************
 */

/*
 **********************************************************************
 ** md5.c                                                            **
 ** RSA Data Security, Inc. MD5 Message Digest Algorithm             **
 ** Created: 2/17/90 RLR                                             **
 ** Revised: 1/91 SRD,AJ,BSK,JT Reference C Version                  **
 **********************************************************************
 */

/*
 **********************************************************************
 ** Copyright (C) 1990, RSA Data Security, Inc. All rights reserved. **
 **                                                                  **
 ** License to copy and use this software is granted provided that   **
 ** it is identified as the "RSA Data Security, Inc. MD5 Message     **
 G** Digest Algorithm" in all material mentioning or referencing this **
 ** software or this function.                                       **
 **                                                                  **
 ** License is also granted to make and use derivative works         **
 ** provided that such works are identified as "derived from the RSA **
 ** Data Security, Inc. MD5 Message Digest Algorithm" in all         **
 ** material mentioning or referencing the derived work.             **
 **                                                                  **
 ** RSA Data Security, Inc. makes no representations concerning      **
 ** either the merchantability of this software or the suitability   **
 ** of this software for any particular purpose.  It is provided "as **
 ** is" without express or implied warranty of any kind.             **
 **                                                                  **
 ** These notices must be retained in any copies of any part of this **
 ** documentation and/or software.                                   **
 **********************************************************************
 */

/* -- include the following line if the md5.h header file is separate -- */
/* #include "md5.h" */

/* forward declaration */
static void Transform(UINT4 *buf, UINT4 *in);

static unsigned char PADDING[64] = {
    0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
};

/* F, G and H are basic MD5 functions: selection, majority, parity */
#define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
#define G(x, y, z) (((x) & (z)) | ((y) & (~z)))
#define H(x, y, z) ((x) ^ (y) ^ (z))
#define I(x, y, z) ((y) ^ ((x) | (~z))) 

/* ROTATE_LEFT rotates x left n bits */
#define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))

/* FF, GG, HH, and IItransformations for rounds 1, 2, 3, and 4 */
/* Rotation is separate from addition to prevent recomputation */
#define FF(a, b, c, d, x, s, ac) \
    {(a) += F ((b), (c), (d)) + (x) + (UINT4)(ac); \
    (a) = ROTATE_LEFT ((a), (s)); \
    (a) += (b); \
}

#define GG(a, b, c, d, x, s, ac) \
    {(a) += G ((b), (c), (d)) + (x) + (UINT4)(ac); \
    (a) = ROTATE_LEFT ((a), (s)); \
    (a) += (b); \
}

#define HH(a, b, c, d, x, s, ac) \
    {(a) += H ((b), (c), (d)) + (x) + (UINT4)(ac); \
    (a) = ROTATE_LEFT ((a), (s)); \
    (a) += (b); \
}

#define II(a, b, c, d, x, s, ac) \
    {(a) += I ((b), (c), (d)) + (x) + (UINT4)(ac); \
    (a) = ROTATE_LEFT ((a), (s)); \
    (a) += (b); \
}

void MD5Init(MD5_CTX *mdContext) {
    mdContext->i[0] = mdContext->i[1] = (UINT4)0;

    /* Load magic initialization constants.
    */
    mdContext->buf[0] = (UINT4)0x67452301;
    mdContext->buf[1] = (UINT4)0xefcdab89;
    mdContext->buf[2] = (UINT4)0x98badcfe;
    mdContext->buf[3] = (UINT4)0x10325476;
}

void MD5Update(MD5_CTX *mdContext, unsigned char *inBuf, unsigned int inLen) {
    UINT4 in[16];
    int mdi;
    unsigned int i, ii;

    /* compute number of bytes mod 64 */
    mdi = (int)((mdContext->i[0] >> 3) & 0x3F);

    /* update number of bits */
    if ((mdContext->i[0] + ((UINT4)inLen << 3)) < mdContext->i[0])
	mdContext->i[1]++;

    mdContext->i[0] += ((UINT4)inLen << 3);
    mdContext->i[1] += ((UINT4)inLen >> 29);

    while (inLen--) {
	/* add new character to buffer, increment mdi */
	mdContext->in[mdi++] = *inBuf++;

	/* transform if necessary */
	if (mdi == 0x40) {
	    for (i = 0, ii = 0; i < 16; i++, ii += 4) {
		in[i] = (((UINT4)mdContext->in[ii+3]) << 24) | (((UINT4)mdContext->in[ii+2]) << 16) | (((UINT4)mdContext->in[ii+1]) << 8) | ((UINT4)mdContext->in[ii]);
	    }

	    Transform (mdContext->buf, in);
	    mdi = 0;
	}
    }
}

void MD5Final(MD5_CTX *mdContext) {
    UINT4 in[16];
    int mdi;
    unsigned int i, ii;
    unsigned int padLen;

    /* save number of bits */
    in[14] = mdContext->i[0];
    in[15] = mdContext->i[1];

    /* compute number of bytes mod 64 */
    mdi = (int)((mdContext->i[0] >> 3) & 0x3F);

    /* pad out to 56 mod 64 */
    padLen = (mdi < 56) ? (56 - mdi) : (120 - mdi);
    MD5Update (mdContext, PADDING, padLen);

    /* append length in bits and transform */
    for (i = 0, ii = 0; i < 14; i++, ii += 4) {
	in[i] = (((UINT4)mdContext->in[ii+3]) << 24) | (((UINT4)mdContext->in[ii+2]) << 16) | (((UINT4)mdContext->in[ii+1]) << 8) | ((UINT4)mdContext->in[ii]);
    }

    Transform (mdContext->buf, in);

    /* store buffer in digest */
    for (i = 0, ii = 0; i < 4; i++, ii += 4) {
	mdContext->digest[ii] = (unsigned char)(mdContext->buf[i] & 0xFF);
	mdContext->digest[ii+1] = (unsigned char)((mdContext->buf[i] >> 8) & 0xFF);
	mdContext->digest[ii+2] = (unsigned char)((mdContext->buf[i] >> 16) & 0xFF);
	mdContext->digest[ii+3] = (unsigned char)((mdContext->buf[i] >> 24) & 0xFF);
    }
}

/* Basic MD5 step. Transform buf based on in.
 */
static void Transform(UINT4 *buf, UINT4 *in) {
    UINT4 a = buf[0], b = buf[1], c = buf[2], d = buf[3];

    /* Round 1 */
#define S11 7
#define S12 12
#define S13 17
#define S14 22
    FF( a, b, c, d, in[ 0], S11, 3614090360); /* 1 */
    FF( d, a, b, c, in[ 1], S12, 3905402710); /* 2 */
    FF( c, d, a, b, in[ 2], S13,  606105819); /* 3 */
    FF( b, c, d, a, in[ 3], S14, 3250441966); /* 4 */
    FF( a, b, c, d, in[ 4], S11, 4118548399); /* 5 */
    FF( d, a, b, c, in[ 5], S12, 1200080426); /* 6 */
    FF( c, d, a, b, in[ 6], S13, 2821735955); /* 7 */
    FF( b, c, d, a, in[ 7], S14, 4249261313); /* 8 */
    FF( a, b, c, d, in[ 8], S11, 1770035416); /* 9 */
    FF( d, a, b, c, in[ 9], S12, 2336552879); /* 10 */
    FF( c, d, a, b, in[10], S13, 4294925233); /* 11 */
    FF( b, c, d, a, in[11], S14, 2304563134); /* 12 */
    FF( a, b, c, d, in[12], S11, 1804603682); /* 13 */
    FF( d, a, b, c, in[13], S12, 4254626195); /* 14 */
    FF( c, d, a, b, in[14], S13, 2792965006); /* 15 */
    FF( b, c, d, a, in[15], S14, 1236535329); /* 16 */

    /* Round 2 */
#define S21 5
#define S22 9
#define S23 14
#define S24 20
    GG( a, b, c, d, in[ 1], S21, 4129170786); /* 17 */
    GG( d, a, b, c, in[ 6], S22, 3225465664); /* 18 */
    GG( c, d, a, b, in[11], S23,  643717713); /* 19 */
    GG( b, c, d, a, in[ 0], S24, 3921069994); /* 20 */
    GG( a, b, c, d, in[ 5], S21, 3593408605); /* 21 */
    GG( d, a, b, c, in[10], S22,   38016083); /* 22 */
    GG( c, d, a, b, in[15], S23, 3634488961); /* 23 */
    GG( b, c, d, a, in[ 4], S24, 3889429448); /* 24 */
    GG( a, b, c, d, in[ 9], S21,  568446438); /* 25 */
    GG( d, a, b, c, in[14], S22, 3275163606); /* 26 */
    GG( c, d, a, b, in[ 3], S23, 4107603335); /* 27 */
    GG( b, c, d, a, in[ 8], S24, 1163531501); /* 28 */
    GG( a, b, c, d, in[13], S21, 2850285829); /* 29 */
    GG( d, a, b, c, in[ 2], S22, 4243563512); /* 30 */
    GG( c, d, a, b, in[ 7], S23, 1735328473); /* 31 */
    GG( b, c, d, a, in[12], S24, 2368359562); /* 32 */

    /* Round 3 */
#define S31 4
#define S32 11
#define S33 16
#define S34 23
    HH( a, b, c, d, in[ 5], S31, 4294588738); /* 33 */
    HH( d, a, b, c, in[ 8], S32, 2272392833); /* 34 */
    HH( c, d, a, b, in[11], S33, 1839030562); /* 35 */
    HH( b, c, d, a, in[14], S34, 4259657740); /* 36 */
    HH( a, b, c, d, in[ 1], S31, 2763975236); /* 37 */
    HH( d, a, b, c, in[ 4], S32, 1272893353); /* 38 */
    HH( c, d, a, b, in[ 7], S33, 4139469664); /* 39 */
    HH( b, c, d, a, in[10], S34, 3200236656); /* 40 */
    HH( a, b, c, d, in[13], S31,  681279174); /* 41 */
    HH( d, a, b, c, in[ 0], S32, 3936430074); /* 42 */
    HH( c, d, a, b, in[ 3], S33, 3572445317); /* 43 */
    HH( b, c, d, a, in[ 6], S34,   76029189); /* 44 */
    HH( a, b, c, d, in[ 9], S31, 3654602809); /* 45 */
    HH( d, a, b, c, in[12], S32, 3873151461); /* 46 */
    HH( c, d, a, b, in[15], S33,  530742520); /* 47 */
    HH( b, c, d, a, in[ 2], S34, 3299628645); /* 48 */

    /* Round 4 */
#define S41 6
#define S42 10
#define S43 15
#define S44 21
    II( a, b, c, d, in[ 0], S41, 4096336452); /* 49 */
    II( d, a, b, c, in[ 7], S42, 1126891415); /* 50 */
    II( c, d, a, b, in[14], S43, 2878612391); /* 51 */
    II( b, c, d, a, in[ 5], S44, 4237533241); /* 52 */
    II( a, b, c, d, in[12], S41, 1700485571); /* 53 */
    II( d, a, b, c, in[ 3], S42, 2399980690); /* 54 */
    II( c, d, a, b, in[10], S43, 4293915773); /* 55 */
    II( b, c, d, a, in[ 1], S44, 2240044497); /* 56 */
    II( a, b, c, d, in[ 8], S41, 1873313359); /* 57 */
    II( d, a, b, c, in[15], S42, 4264355552); /* 58 */
    II( c, d, a, b, in[ 6], S43, 2734768916); /* 59 */
    II( b, c, d, a, in[13], S44, 1309151649); /* 60 */
    II( a, b, c, d, in[ 4], S41, 4149444226); /* 61 */
    II( d, a, b, c, in[11], S42, 3174756917); /* 62 */
    II( c, d, a, b, in[ 2], S43,  718787259); /* 63 */
    II( b, c, d, a, in[ 9], S44, 3951481745); /* 64 */

    buf[0] += a;
    buf[1] += b;
    buf[2] += c;
    buf[3] += d;
}

/*
 **********************************************************************
 ** End of md5.c                                                     **
 ******************************* (cut) ********************************
 */

/*
 * Copyright (c) 2008 Neil Richardson (nrich@iinet.net.au)
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy 
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights 
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 
 * copies of the Software, and to permit persons to whom the Software is 
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 
 * IN THE SOFTWARE.
 */

#include "common.h"

/*
 * hexstr = lash.MD5.str2hex(str)
 *
 *  calculates the MD5 hash of str and
 *  returns it as a lowercase hexstring
 */
int MD5String(lua_State *L) {
    char hashstring[33];
    size_t length;
    unsigned char *data = (unsigned char *)luaL_checklstring(L, 1, &length);
    MD5_CTX mdContext;
    char *h;
    int i;

    MD5Init(&mdContext);
    MD5Update(&mdContext, data, length);
    MD5Final(&mdContext);

    for (h = hashstring, i = 0; i < 16; i++, h += 2)
        sprintf(h, "%02x", mdContext.digest[i]);

    hashstring[32] = '\0';

    lua_pushstring(L, hashstring);
    return 1;    
} 

/*
 * hexstr,err = lash.MD5.file2hex(filename)
 *
 *  calculates the MD5 hash of the contents of filename
 *  and returns it as a lowercase hexstring
 *  on error return nil,errorstr
 */
int MD5File(lua_State *L) {
    int i;
    char hashstring[33];
    const char *filename = luaL_checkstring(L, 1);
    char *h;

    FILE *inFile = fopen(filename, "rb");
    MD5_CTX mdContext;
    int bytes;
    unsigned char data[READ_SIZE];

    if (inFile == NULL) {
	char err[ERR_STRING_LEN];	
	strerror_r(errno, err, ERR_STRING_LEN);	

	lua_pushnil(L);
	lua_pushfstring(L, "Cannot open file '%s' for input: %s", filename, err);
	return 2;
    }

    MD5Init(&mdContext);
    while ((bytes = fread (data, 1, READ_SIZE, inFile)) != 0)
	MD5Update(&mdContext, data, bytes);

    MD5Final(&mdContext);
    fclose(inFile);

    for (h = hashstring, i = 0; i < 16; i++, h += 2)
	sprintf(h, "%02x", mdContext.digest[i]);

    hashstring[32] = '\0';

    lua_pushstring(L, hashstring);
    return 1;
}

